I have a single canister Reef Octopus Calcium Reactor. I am using a Milwaukee PH controller. I use Carbi Sea ARM course media. I have my controller set to 6.5 ph. I also dose kalkwasser from my ATO using my Apex and Reefkeeper dual float switch. I use an 18 gallon rubbermaid container filled with approximately 15 gallons of RODI water and Kalkwasser @ 1-1.5 tablespoons per gallon. I started using ATO and Kalk approximately a month ago.
Around a month ago, I re-calibrated my ph probe for my PH controller with NIST certified 4 ph and 7 ph solution. Reinserted the probe and I was measuring 6.0 ph in the reactor. I removed the probe and inserted the probe from my Apex unit calibrated 3 days prior with the same NIST certified 7 ph and 10 ph solution (runs in my sump). And it read 6.1 ph. So apparently over the course of a couple months or so, the calibration must of gotten .5 out of wack. All of my SPS/LPS coral looked great. Water parameters tested at ALK-15, Mag-1380-1420, and Cal- 430-440. All using Salifert test.
With the freshly calibrated ph probe from the Milwaukee controller installed and ph of fluid inside the reactor, I made sure the controller was set to 6.5 and I let the effluent drip until the ph was raise from 6.0 to 6.5. Also, to note, effluent inside reactor was clear before and after recalibration. Media was not mush or milky.
For the past couple of weeks, I have noticed a decline in my coraline algae. Also a slower than before growth in my SPS coral. All appear to be very healthy still, but growth has been halted slightly. Water parameters currently test Alk-9.6, Mag -1320, and Cal -1320.
I spoke with a very knowledgeable reef store owner concerning my problem and my troubles with my ph in my reactor and that I had it dialed in with 2 different probes. He told me to test my effluent. I should be between 30-40 dkh. I tested today. It tested at 11 dkh with my salifert test kit. Also, looking at my salifert test kit...the test chart stops at 15.6 How do I test for 30-40 dkh using a Salifert kit?
4 things that are crossing my mind.
1. The solutions I used to calibrate my probes might be incorrect? They are NIST certified purchased online. 6.0 to 6.5 is a huge jump for ARM. The ph may of been correct previous to recalibration. I had GREAT growth before.
2. My effluent drip rate was too fast not allowing the media to breakdown to become saturated before leaving reactor. It was adjusted for 60-100 ml per minute. As per suggested by many articles as a good starting point.
3. My calcium absorbtion rate has increased quite a bit due to new frags/new growth that I need to drop the ph in the reactor to break the media down quicker?
4. I need to dose more kalkwasser in my ATO reservior to keep up with demand?
I really feel the reactor is out of wack. Any suggesions or answer to my questions.
Thanks so much for your help.
120 gallon mixed lps/sps reef
50 gallon sump
reef octopus 3000int skimmer
reef octopus single chamber calcium reactor w/ ARM media
Dual 400 watt metal halides 20k running 6 hours daily with dual actinics running 2 hours before and 4 hours after mh cycle.......